1. Cells need to get and in through the cell membrane. nutrients gases
INTO & OUT OF THE CELL!!!
Cells need to get and in through the cell membrane.
nutrients
gases
must be able to leave the cell.
Wastes .
The cell membrane is “picky” about what enters and leaves the cell. The membrane is
selectively permeable.

2. Concentration EQUILIBRIUM DIFFUSION
Cells live with liquids all around—water/salts/gases are dissolved in this liquid.
Concentration
is a measure of how much of 1 substance is dissolved in a certain amount of another substance.
Cells like to keep things equal!! This is called
EQUILIBRIUM
When things are unequal—things move to make it equal again!!
DIFFUSION
This is known as
Molecules moves from areas of high concentration ( ) to areas of lower concentration ( )
crowded
spread out

3. What concentration looks like with a cell.

4. Diffusion in Action.

5. For example--
More molecules outside the cell!
Molecules equal out!!
If the substance moving is WATER—special kind of diffusion known as--
OSMOSIS

6. ENERGY
Diffusion & Osmosis—require no just happens to equal things out!!

7. Discussion Question-How would you say a cell membrane and a window screen are similar?